Sometimes the best way to identify a good or bad purchase is to try and put it into words. If you can’t justify your purchase with a convincing written statement, maybe your money should stay in your wallet.

Big purchases, especially impulse ones, can undo all of the time you spent saving. On his blog, the Financial Samurai suggests you write out what you want to buy and explain why you should buy it. The written argument should not only be convincing for yourself, but also convincing for anyone else who reads it. Show it to a friend, a family member, or even somebody online. If they all agree, you know you’re not making a mistake. Taking the time to do this keeps you from being impulsive, and the act of writing forces you to think deeper about the purchase in question. So the next time you see something you want to buy, don’t break out your wallet, break out a pen and paper.